Method of and apparatus for coating paper-board with paraffin or the like



J. W. LOW. METHOD OF AND APPARATUS FOR COATING PAPER BOARD WITH PARAFFIN.

' APPUCATION FILED JUNE 4,1917- 1,336;528. Patented Apr. 13, 1920.

3 SHEETS-SHEEf l- 5 Inventor J. W. LOW.

METHOD OF AND APPARATUS FOR COATING PAPER BOARD WITH PARAFFIN.

APPLICATION FILED JUNE 4, I91?- 1,336,528, Patented Apr. 13, 1920.

3 SHEETS-SHEET 2.

I m w I'IHHIIT IWI IHH I M!HITIHMITIH. W5: 6 Dog I H Li ILL'C 75607." m2 11 000 J. w. LOW. METHOD OF AND APPARATUS FOR COATING PAPER BOARD WITH PAR'AFFIN.

APPLICATION FILED JUNE 4. I917- 1,336,528, Patented Apr. 13, 1920.

3 SHEETS-SHEET 3.

MM/leases:

UNITED STATES PATENT oiTIoE.

JOHN w. LOW, or J'OLIET, ILLINOIS.

METHOD OF A'Iil'D APPARATUS FOR COATING PAPER-BOARD WITH PARAFFIN OR THE LIKE.

Specification of Letters Patent.

Patented Apr. 13, 1920.

Application filed June 4. 1917. Serial No. 172,642.

To all whom it may concern: Be it known that I, JoH I- W. Low, a citizen of the United States, and a resident of Joliet, in the county of Will and State of Illinois, have invented certain new and useful Improvements in Methods of and Apparatus for Coating Paper-Board with Paraflin or the like; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the characters of reference marked thereon, which form a part of this specification.

This invention relates to a novel method of and apparatus for applying paraflin to aperboard for the purpose of producing a board which is impervious to moisture and grease, and which also protects the contents of packages or containers made therefrom from deleterious atmospheric properties.

An example of containers for which the treated paper board may be used is containers for butter, butterin, and like relatively solid oleaginous substances.

Among the objects of the invention is to provide a process or method of applying paraflin to paperboard in such a way as to increase its moisture and grease resisting properties beyond treated paperboard heretofore proposed, and at the same time to produce a board which has a relatively thick or heavy coating of paraflin and whic is applied in such a way as to provide a smooth, uniform and attractive surface to which the commodity of the container does not adhere, and to which extraneous sub stances do not adhere and may therefore be kept in a sanitary state or condition.

A further object of the invention is to provide a novel mechanism for applying the parafiin to the paperboard, the elements of whicl1 are so organized as to produce the resultant productfhereinabove specified.

The invention consists in the steps of the process or method hereinafter described and in the: combination and arrangement of the mechanism shown in the drawings and described in the specification, and the invention is pointed out in the appended claims.

. In said drawings,

Figure '1 is a plan view of a machine embodying my invention.

Fig. 2 is a central longitudinal vertical section thereof.

Fig. 3 is a transverse section on the line 3-3 of Fig. 2. i

Fig. 4 is a detail section on the line lsof Fig. 2.

The method or process of applying paraflin or like waterproofing material to paperboard, in accordance with my invention, conslsts 1n its entirety in the steps of passing the paperboard to be treated through a coatmg bath consisting of a solution of hot paraffin or other like material, subjecting the paperboard while in the coating bath to substantial pressure between hard rotating surfaces, such as steel rollers, for the purpose of driving off excess coating material I from the sheet and expelling the globules of air from the films of coating material and also forcing or pressing some of the coating material into the body of the sheet; thereafter again passing the sheet through the coating bath after it leaves said rollers; thereafter subjecting the coated sheet to pressure between cushioned rotating sur-- faces to remove excess coating material and to spread the film of coating material uniformly on the surfaces of the sheet; thereafter delivering the coated sheet While hot directly to a body of cold water to chill the ered to a stacking table or shelf.

The machine herein shown as embodying my invention in one practical adaptation comprises, in general terms, a relatively shallow pan .to contain the coating bath, having means to heat the material of the bath; a pair of rollers supplied with material of the bath, with means to'guide the paperboard thereto; a guide for carrying the coated paperboard from said rollers to a second set of rollers having relatively soft or cushioned faces and located outside the bath; a tank in advance of said pan for con- -taining a relatively large body of cold water; with suitable means for carrying the coated paperboard delivered from the last mentioned pairs of rollers downwardly through the body of water, and a final pair of rollers at the rear end of said tank between which the coated and chilled paperboard is carried and by which the films of water are driven off from thepasteboard, with means for guiding the chilled and coated paperboard from the carrying means in the tank to said last mentioned rollers.

The pair of rollers subjected to the coating bath are located between the front and rear end of the pan which contains the bath, and the action of said rollers is to force or drive excess coating material from the sheet which the sheet receives from the bath to force globules of air from said material caught up by the sheet as it passes into the bath, and, if desirable to further press the material into the body of the sheet to a greater extent than would occur if no pressure devices were present; and after the sheet thus initially coated leaves the rollers it is again subjected to the coating bath in the part thereof in rear of said rollers to receive a second coating. This second coating is, by the cushioned rollers that are located between the coating bath and chilling bath, uniformly distributed over the sur faces of the sheet and, inasmuch as the sheet is hot, due to its presentation to the hot bath, the coating material is further pressed into the fibers of the body of the sheet. As a result, the sheet leaves the cushioned rollers with a relatively thick surface coating and with the surface fibers of the sheet carrying a substantial amount of the coating material. In this way I am enabled to improve the waterproofing qualities of the paper, and, at the same time, to produce smooth films of the coating material on the surfaces of the sheet. The quantity of cold water in the chilling bath is such as to absorb the heat transmitted to the sheet during its passage through the coating bath, and the passage of the sheet between the relatively hard faced rollers at the rear end of the chilling bath tank serves to drive offthe water from the sheet and also to further smooth out any irregular or wavy surfaces of the sheet.'

The temperature of the coating bath depends somewhat upon the thickness of the paperboard being treated. The temperature of the bath should be sufiicient to hold the wax which is pressed into the sheet and that which lies in films on the surfaces of the 175 degrees to 185 degrees F. gives good results. I have found that the sheets after emerging from the chilling bath are completely cooled sothat the sheets may be piled one upon the other without danger of developing heat in the stacks which, if present, would tend to give the surfaces of thecoated sheets a hazy appearance or dull finish. v I

The drawings illustrate a machine which, in practice, has shown high efficiency to pro.- duce the waterproof glossy product desired, and in the following description reference will be had to the specific details of theillustrated machine. It will be understood, however, that said details maybe varied within the spirit and scope of the invention and of the claims hereto appended.

As shown in said drawings, 10 designates a relatively shallow pan which contains the coating bath and 11 designates a tank of large capacity to contain the chilling bath, said tank being located in rear of the pan. Said pan is supported at about the level of the top of the tank on a suitable frame designated as a whole by 12, and the pan is adapted to be filled and kept filled with the coating solution. The coating solution may be heated in any suitable manner, as by means of steam conducted thereto through a coil of steam pipes 14 provided with a valved supply pipe 15.

Located within said pan, and between the front and rear sides thereof, with their line of peripheral contact submerged in the coating bath, are a pair of upper and lower rollers 16, 17, respectively. The shafts 19, 20 of said rollers are rotatively mounted in suitable bearings carried by standards 21, 21

that are fixed in any suitable manner to the bottom of the pan and rise therefrom. Said shafts carry near one of said standards a pair of meshing gears 22, and one of the shafts is provided with a driving pulley 23 through which power is applied to rotate.

said rollers in opposite directions.

25, 26 designate upper and lower rollers of a pair which are arranged at the rear end of the pan 11 above the coating baththerein and between said pan and the chilling bath tank 11. The shafts 27, 28 of said rollers are mounted in bearings carried by stand ards 30, 30 which may be attached in any suitable manner to the machine frame. The bodies of said rollers are preferably made of steel or other hard rigid substance and are covered with heavy face layers of a cushioning material, preferably a relatively coarse felt. The shafts of the rollers are provided with meshing gears 33, 33, and the shaft of one of the rollers, the lower roller as herein shown, carries fast and loose pulleys 34, 35 through which power is communicated to the airs of rollers to drive the same in opposite directions. 7

The upper roller may be pressed upon the lower roller, in addition to the force due to 50 rear end of the tank by brackets 57.

6'5 opposite directions.

its weight, by springs 36 that press on the bearing boxes ofsaid upper roller. The sheet after leaving the rollers 16, 17 is directed to the bight of the rollers 25, 26 between upper and lower sets 37 of upwardly inclined guides of general ogee shape, which, as herein shown, are supported on the standards 21 and on short upright bars 38 arranged in front of the cushion rollers.

1.0 The coated sheet after being discharged from the rollers 25, 26 is carried through the chilling bath by a carrier device which consists as herein shown of a plurality of upper and lower sets of tapes 40, 41, respec- 15 tively, the adjacent laps of which travel parallel throughout the length of the tank in an indirect path so as to carry the sheet deeply into the chilling bath. The upper sets of tapes are trained about the rollers 41, 42, 43 that are mounted in suitable bearings carried by the tank and arranged at the angles of atriangular figure; the rollers 41 and 43 being idle rollers. The lower set of tapes are carried by upper rollers 45, 46 arranged at the front and rear ends, respec- 80 with the lower or active laps of the other set or upper tapes 40. Said rollers for the lower tapes are rotatively mounted in suitable bearings carried by the side walls of the tank, and the shafts of the rollers 42, 46

are provided at one side of the tank with meshing gears 48. One of said shafts, the shaft of the roller 42, as shown, is provided with fast and loose pulleys 49, 50 through which power is transmitted to drive the rollers 42, 46 in opposite directions and to cause the active laps of said tapes to travel in the same directions, or rearwardly,

through the tank.

51, 52 designate upper and lower rollers arranged at the rear of and above the chilling bath tank. The shafts 53, 54 of said rollers are mounted in suitable bearings carried by standards 55 which rise from and are attached to a shelf 56 that issupported at the The saidshafts 53, 54 carry intermeshing gears 55, and one of the shafts carries tight and loose pulleys, 58, 59, through which power is transmitted to drive the rollers 51, 52 in Said rollers are preferably faced with relatively hard rubber, it being desirable .to secure solid coating faces having slight resilience and good tack to insure the withdrawal of the chilled sheet 60 delivered thereto and to drive off the water .8 guide fingers 60, 61, respectively, which serve to direct the sheet to the bight of the rollers 51, 52. A drain pan formed by said bracket 56, beneath said rollers 51, 52, catches the water pressed from the sheet by said rollers and drains it back to the tank.

In the operation of the machine the sheets are delivered through the hot coating bath to the rollers 16, 17 over an inclined feed board 62, the lower end of which dips into the coating bath. The coating material clings to the sheet in its passage through the bath in heavy thick films on the surfaces thereof, and during the passage of the coated sheet between the rollers 16, 17 excess coating materiahis driven, off the sheet by the said rollers, and also globules of air which are caught in said films. If these globules of air were allowed to remain in the films they would break and leave small craters over the surfaces of the sheet, which would produce a mottled effect and also diminish the water-proof qualities of the coating. Said rollers have hard faces and serve also to press some of the hot coating solution into the sheet. When the sheet leaves the rollers 16 and 17, but little of the coating material lies on the surfaces of the sheet, but some ofsaid material has been pressed into the fibers of the sheet; The weight of the upper roller 16 will usually be sufficient to drive the excesscoating material and air globules from the sheet and to press said material into the fibers thereof, but the force of the weight may be supplemented by spring pressure if found necessary or desirable. After the sheet leaves the rollers 16 and 17 it is again passed through the coating bath, between said rollers and the cushioned rollers 25, 26 and the sheet receives on its surfaces other films of the coating material. The sheet is guided by the guide finger 37 to the rollers 25, 26 and is by said rollers sub'ected to a moderate cushioning pressure w ich serves to drive off some of the excess coatiiig material from the surfacesthereof and to uniformly distribute the films of coating material, which are still in a liquid state, due to the temperature of the bath, on the surfaces of thesheet, so as to produce a smooth, finished product. p a

The sheet is thereafter delivered directly to the carrying ta es and is thereby carried into and-through the chilling bath. In order that the sheet -may be delivered from the rollers 25, 26 directly to said carrying tapes, and in order to avoid the use of directing guides, the standards 30 in which thesha'fts of said rollers 25, 26 are mounted are inclined rearwardly so that a downwardly inclined direction is given to said coated sheet as it leaves the said rollers 25, 26, and this inclination is such, relatively to the inclination of the parallel active laps of the upper and lower sets of tapes that the sheet is delivered directly into the bight of said tapes,

without the necessity of employing additional guides. The sheet is chilled in its passage through the relatively large body of cold water, which is maintained at as low a temperature as is practicable and is by said tapes delivered between the guides 60, 61 to the pressing rollers 51, 52, from whence the finished sheets are delivered on to an inclined receiving shelf 65.

In order that the tapes 40, 41 may be held in place on their rollers and prevented from shiftin in directions endwise of the rollers, said ro lers are shown as provided with annular beads 66 and said tapes form over said beads in the manner best shown in Fig. 3.

Power may be applied separately to the several pairs of driven rollers 25-26, 42-46 and 5-1, 52 from an overhead counter shaft and properly directed belts, or said several rollers may be geared or belted to be driven from a single source of power. The driven roller of the pair of rollers 16, 17 is shown as driven from the lower roller of the pair 25, 26 by a belt or sprocket chain 67 that is trained over the pulley.23 and a pulley 68 on the shaft of the lower roller 26.

Cold Water is delivered to the tank 11 through a valved feed pipe 69 and may be drained therefrom through an overflow pipe 70, whereby the water level in the tank is maintained.

I claim as my invention,

1. The process of treating paperboard with parafiin or like coating material, which consists in the steps of sub ecting a sheet of paperboard to the application of a hot coating material; subjecting the sheet to pressure while so subjected to said coating material to drive off surplus coating material and to press the material into the body of the sheet, again subjecting said sheet to the coating material, thereafter pressing excess coating material from the coated sheet, and finally cooling the coated sheet.

2. The process of treating paperboard with paraffin or like coating material, which consists in the steps of immersing a sheet of paperboard in a bath of hot coating material; subjecting the sheet to pressure while in the bath; passing the coated and pressed sheet again through the hot coating bath, and finally assing the coated sheet into and through a c illing bath.

- 3. The process of treating paperboard with parafiin or like coating material, which consists in the steps of immersing a sheet of paperboard in a bath of hot coating material; subjecting the sheet to pressure while in the bath; passing the coated and pressed sheet again through the hot coating bath,

- subjecting the coated sheet outside said bath to pressure between rotating cushioning surfaces, and finally passing the coated sheet into a chilling bath.

4. The process of treating paperboard with paraflin or like coating material, which consists in the steps of immersing a sheet of paperboard in a bath of hot coating material; subjecting the coated sheet in said bath to pressure between hard rotating surfaces to drive off excess coating material and to force said material into the body of the sheet; subjecting the 'coated sheet, outside of the bath, to pressure between rolling cushioned surfaces, and, finally, passing the coated sheet into and through a chilling bath.

5. The process of treating paperboard with'parafiin or like coating material, which consists in the steps of immersing the paperboard in a bath of hot coating material; subjecting the coated sheet in said bath to pressure between hard rotating surfaces to drive off excess coating material and to force said material into the body of the sheet subjecting the coated sheet outside of the bath to pressure between rolling cushioned surfaces; immersing the coated sheet in a chilling bath, and finally subjecting the chilled sheet to pressure between hard rotating surfaces.

6. he process of treating paperboard with paraflin or like coating material, which" consists in the steps of immersing a sheet of paperboard in a" bath of hot coating material; subjecting the sheet to pressure while in the bath; passing the coated and pressed sheet again through the hot coating bath, subjecting the coated sheet outside said bath to pressure between rotating cushioning surfaces, passing the; coated sheet into and through a chilling medium, and finally subjecting the chilled sheet to pressure between hard rotating surfaces to drive the water therefrom.

7. A machine for treating sheets of paperboard with parafiin or like coating material comprising an open top tank for containing a body of cold water; a pan for containing hot coating material located near the level of the top of said tank; a pair of hard faced rollers whose line of peripheral contact is submerged in the' coating material; a pair of cushion faced rollers located between said hard faced" rollers and said tank and arran ed above the level of the tank; means to guide a sheet through the coating material to said hard faced rollers; means to guide the sheet through said coating material from said hard faced rollers to said cushion faced rollers and a carrier for carrying the sheets through said body of cold water, to which the sheets are delivered by said .cushion faced rollers.

8. A machine for treating sheets of paperboard with paraffin or like coating material comprising an open top tank for containing a body of cold water; a pan for containing hot coating material located near the level 7 through rollers whose line of peripheral contact is submerged in the coating material; a pair of CllShlOIl faced rollers located between said hard faced rollers and said tank and arranged above the' level of tank; means to guide a sheet through the coating material to said hard faced rollers; means to guide the sheet through said coating material from said hard faced rollers to the cushion faced rollers; a carrier for carrying the sheets said body of cold water; a pair of hard faced rollers located at the rear end of said tank, and guide means for directing the sheets from said carrier to said latter rollers.

9. A machine for treating sheets of paperboard with paraflin or like coating material comprising a pan for containing hot coating material, a pair of rollers therein be tween which the sheet is passed; a tank for containing a body of cold water; a pair of rollers between said pan and tank having cushioned faces between which the sheet is passed on its way from the way to said tank, with means for guiding the sheet from the first mentioned rollers to the second pair of rollers; means for carrying the coated paperboard downwardly through the body of cold water; and a third pair of hard faced rollers at the rear end of said tank between which the sheets are passed to drive off the water therefrom, said cushioned faced rollers being mounted on standards which are inclined toward the open tank.

In testimony whereof I claim the foregoing as my invention, I hereunto append my signature in the presence of two witnesses at Joliet, Illinois, this 28th day of May 1917. r v

JOHN W. LOW.

Witnesses WM. LIBURS, DIETTA DAVIDSON. 

